Public interest in "The Real Housewives" of hither and yon notwithstanding, the well-behaved trophy wife is not, generally speaking, a character we're dying to know more about. And beautiful Pippa Lee (Robin Wright Penn) is a trophy wife of the highest order. Polite, restrained and seemingly vacant, the heroine of writer/director Rebecca Miller's The Private Lives of Pippa Lee, cooks a mean butterflied lamb, keeps a meticulous house and floats around in silky pajamas, all the while gazing fondly at her cutely cranky husband Herb (Alan Arkin), a former publisher 30 years older than she is, as if he were the pet and not she.

During the dinner party that opens the movie, the couple's pompous writer friend Sam (Mike Binder) hoists his glass to Pippa and describes her as still an enigma after 25 years of friendship. Sam's sense of Pippa as enigma probably has a lot to do with the fact that she's never been interested in sleeping with him, but he raises a fair point. Pippa and Herb recently moved from New York to a cloistered Connecticut retirement community, and the high point of Pippa's day is monitoring Herb's blood pressure. Most women in their mid-40s would find this existence pretty dreary. There must be something beyond Pippa's cheery façade.

In her relatively short directing career, Miller has shown a knack for making the people we think we don't want to know  like the father and daughter fighting incestuous urges in The Ballad of Jack and Rose  into not just plausible protagonists but people we truly care about. We assume Pippa has coasted through life on not much more than her beauty. The Lees' adult daughter, photojournalist Grace (Zoe Kazan), is crazy about her daddy, but when she directs her attention at her mother it's usually to give her a scathing look. Pippa's neurotic friend Sandra (Winona Ryder) chafing under her own marriage to the overbearing Sam, describes Pippa as "peaceful and good," ostensibly with admiration, but the undercurrent is "you're complacent and boring." We expect to agree, yet Pippa ends up being one of the most intriguing cinematic women of the year. (See TIME's 2009 Holiday Movie guide.)

As with the women in Miller's lauded triptych Personal Velocity  which, like this movie, she adapted from her own book  Pippa is a woman on the verge of either a breakdown or an epiphany. The private lives of the title refer to both flashbacks to her youth (in which she's played by that stunning Gossip Girl Blake Lively) and to the odd, secretive relationship she's cautiously beginning with herself.

Before there was Pippa Lee, there was Pippa Sarkissian, adoring daughter of a Dexedrine addict named Suky (Maria Bello), who treated Pippa as a living doll and an accessory to an imagined life. "I was the only one who knew she was pretending to be in a commercial or a movie half the time," Pippa tells us in voiceover. Eventually, teenage Pippa flees her childhood home for her Aunt Trish's (Robin Weigert, Deadwood's Calamity Jane). But that's essentially her only act of strength before beginning a new phase of being passed around by people other than her mother.

In the past, Miller has relied on handheld camera work to create a sense of intimacy. Here her cinematographer, Declan Quinn, spares us the shaking, but frequently slides the camera between adjacent sets. We travel from the bed one tousled blond woman (Suky) collapsed in a bed to another (Pippa), waking in another town and another decade. It's a neat trick to suggest life as a continuum  Pippa is ruled by guilt and a need to emulate her mother's happy "commercial" existence, aiming for perfection but without the pill popping  but it also represents what's going on in Pippa's mind. In looking back at her own history, she's fracturing and so is her picture-perfect life. She's got to shed the act.

With themes like this, the movie could have gotten bogged down in a desire to convey profundities. But Pippa is too good-humored and lovingly wise to be pretentious. Suky is a tragic figure, but Bello is very funny. Arkin looks silly in his flashback hairpiece, but he gives Herb the nuance he needs, irascible charm all bound up in entitlement. Keanu Reeves plays Chris, the "half-baked" son of Pippa's neighbor Dot (Shirley Knight), whose lack of guile makes him unexpectedly good company for Pippa as she loses her own social graces.

It's hard to imagine the movie succeeding without Wright Penn. She and Lively are both blond, blue-eyed and beautiful, but the resemblance stops there. Clearly, though, Wright Penn studied Lively's movements, because she uses various tricks, echoing her arched eyebrows or open, camera-ready smile, to make up the physical differences between them. It's a generous act  the more skilled actress reaching out to the younger for the sake of the character. Wright Penn has been in the public consciousness for more than 20 years (Buttercup!), but she herself has been something of an enigma. She seemed, at times, hardly to want to be an actress, letting her private life lead the way while she clutched her potential close to her chest. Pippa should be a career changer. Wright Penn's cards are finally on the table, and it looks like a full house.